Do you find that some scenes in sitcoms are skipped on tv?

Because SitComs are lazy in all aspects and lowest common denominator, and the pauses for the mandatory canned laugh tracks take up 30% of the episode.

Most likely some scenes are shortened so they can make room for more commercials. They do this to Seinfeld on TBS as well. TBS also edits out the famous intro song of Friends

What @rockfan says. When they go into syndication, the networks that buy the rights pay an enormous amount, so they try to recoup the cost with increased advertising. Even 5 to 15 seconds saved here and there can be filled with expensive advertising.